Various techniques are known in the art for applying panels to cover a deck or to function as the siding of a wall. Slate is a particularly desirable type of panel. It is difficult to mount on a deck by virtue of being a natural product, lacking true uniformity in dimensions, brittle, and of varying hardness and characteristics. Conventional mounting is done by nailing the individual slate panel to a deck through holes previously formed in the slate. The procedure has not changed essentially for centuries. An alternative procedure is to use hooks that are attached directly to the deck, and that engage the edges of the slate. There are significant drawbacks to the hook system, and also to the nailing procedure, which requires much skilled labor and involves breakage.